Georg bernadotte soelberg



(No Model.)

GB.SOELBERG. ELASTIC INLAY FOR BACKS OF BOOKS.

No. 598,185. Patented Feb. 1,1898.

Warren STATES PATENT Unmet GEORG BERNADOTTE SOELBERG, OF COPENHAGEN,DENMARK.

ELASTIC INLAY FOR BACKS OF BOOKS.

SPECIFICATION forming part of Letters Patent No. 598,185, dated February1, 1898.

Application filed May 20, 1896. Serial No. 592,332. (No specimens.)Patented in Norway March 30, 1896, No. 5,064; in Germany April 18,1896,110. 90.429; in France April 24,1896,N0. 255,841; in Sweden AprilZ5,1 896,No.7,919; in England ApriLZS, 1896, No. 8,792, and in DenmarkFebruary 25, 1897,1To. 980- .1897, No. 980;) and I do hereby declare thefollowing to be a full, clear, and exact description of the invention,such as will enable others skilled in the art to which it appertains tomake and use the same, reference being had to the accompanying drawings,and to letters of reference marked thereon, which form a part of thisspecification.

My invention has relation to the art of bookbinding, and moreparticularly to the backing of books.

As is well known, in order that a book may be opened flat, orsubstantially so, it is essential that the back should possess therequired flexibility or elasticity and that the jointbetween the coversand said back should be very flexible and yet possess the requiredstability or durability, so as not to break.

It has before my invention been the practice to constructthe backs forbooks of a plurality of layers or strips of asuitable flexible material,as cardboard, stout paper, and the like glued together, or of aplurality of such layers of material of successively-decreasing Widthglued along their edges only. In both constructions the layers ofmaterial, when glued together asdescribed, were molded into thepropershape by pressure around a hollow heated mandrel. In the mode ofconstructing the backs of books first referred to the gluing together ofthe several layers of material destroys in a great measure theflexibility and elasticity of the structure, so that the back of a bookis liable to break aftera very'short time. On the other hand, when theback of a book is' constructed as last described and glued along theedges only the superposed layers of material of gradually-reducedwidthare liable to part from one another, while the construction is a verylaborious and costly one. My invention is designed to overcome thesedifficulties; and it has for its object certain improvements whereby thestrength of the backs for books is materially increased, the cost ofmanufacture or construction reduced, and whereby a very elastic back anda flexible hinge-joint between such back and the cover is obtained, aswill now be fully described, reference being had to the'accom" panyingdrawings, in which- Figure 1 is a cross-sectional view of the back of abook before it is pressed or molded into shape. Fig. 1 is a schematicend view illustrating another mode of constructing the back. Fig. 2 is.a cross-sectional view of the finished back. Figs. 3 and 4 show by endviews the complementary parts of a die by means of which the backs forbooks are shaped or molded, and Figs. 5 and 6 are like viewsillustrating the operation of shaping or molding.

In carrying out my invention the back is formed of asingle sheet of moreor less springy material a-as stout paper, thin cardboard, or thelike-folded upon itself a number of times sufficient to form the desirednumber of superposed layers of the required width, as shown in Fig. l,the superposed layers being glued together along their edges only, andto the inner or top layer is glued a strip b of a suitable textilematerial, as more clearly shown in Fig. 3*, so that the edges thereofwill project from the opposite sides of such top layer for connectionwith the covers for clearlyin Fig. l, the whole being then pressed flat.The flat-pressed back B, Fig. 1, thus formed is molded to the propershape in the following manner through the medium of suitableinstrumentalities, to wit:

The flat-pressed back B is bent around a the book, as shown in Figs. 1and 2 and more suitable mandrel or male die 0, provided with 5 alongitudinal groove 0, in such manner that. the glued edges of the backwill lie on opposite sides of said groove. The back B, with its mandrelor male die 0, is then placed with the groove 0 uppermost into a femaledie D,

composed of two complementary parts 01 d, preferably hinged together ate in any suitable manner, as by means of a strip of flexible material,said complementary parts havin g outer downwardly-convergi n g faces (Zand inner concave faces d, corresponding to the shape to be given to theback. The female die is now placed, as shown in Fig. 5, into apress-frame F, composed of a bed-plate f and two side pieces or cheeksf, whose inner faces correspond in inclination to the inclination of theouter faces of the female die D,

- a presser-bar h being placed in the groove of the die or mandrel c, towhich bar pressure is applied by any suitable well-known means, wherebythe die D is forced into the frame F to close its complementary parts cl01 around the back and the die 0, whereby said back is pressed to thedesired shape, as shown in Fig. 6. In practice I prefer to interposebetween the back B and the die D a lining g of cardboard or the like,and a greater or less number of lining-sheets 9 may be employed to fillout the die D if the back B is of less diameter than the space formed bythe concave inner faces d of said die when closed or approximatelyclosed together or when the back B is to have a more or less flattenedshape, mandrels or dies 0 of different diameters being used.

In the operation of bending the flat-pressed back around the mandrel ordie 0 the several superposed layers a of material will be displacedrelatively to each other along the nonadherent portions, as shown inFig. 2, and owing to the construction of the die D the greatest pressurewill be along the glued edges of the back. It will readily be seen thatby the means described the shaping of the back is effected in a veryrapid and simple manner.

After the operation of shaping, the finished back is allowed to dry at anormal or moderate temperature.

A book-back B constructed as described is extremely elastic, as isapparent from the position assumed by the superposed layers a ofmaterial, Fig. 2, relatively to each other when the book is opened, thesuccessive con centric segments being of gradually-reduced diameter inan inward direction. Inasmuch as the several layers a are formed of acontinuous sheet of material, very strong hinge edges are formed thatare much more durable than those of any book-back known to me, while aperfectly flexible hinge-joint is obtained. This is due tothe more orless springy nature of the individual layers, each of which is capableof yielding under the pressure when the back is spread on opening thebook and of returning to its normal position when relieved of suchpressure on again closing such book.

If the material used for the backB is very strong, hence not readilybent, the sheet before folding and gluing may be more or less moistened.

In order togive to the back B a permanent set, the sheet of materialbefore being folded upon itself and glued along its edges may beslightly moistened, and when folded and glued as described it is pressedflat between hot plates and then shaped while still hot, as set forth.The moistening of the sheet of material may, however, be dispensed withand the same results obtained, and at the same time the care necessaryto the application of the glue along the edges only avoided by spreadingthe glue over the whole of one face of the sheet of material used andinserting strips of paper between each two folds to prevent such foldsfrom becoming glued together, as shown in Fig. 1, wherein a indicatesthe sheet of material folded upon itself and a the strips of paperapplied, said strips being of course narrower than the width of thefolded layers, so that the edges a will be glued together when thefolded sheet is compressed. This has the further advantage in that aback so constructed is of greater strength and elasticity, while theglue supplies the necessary moisture to give to the back its permanentset after shaping and drying, the overlapping strip of textile or otherlike material I) being glued to the inner or upper fold.

It will of course be understood that Fig. 1 is a mere schematic viewillustrative of the mode of construction last described.

Having thus described my invention, what I claim as new therein, anddesire to secure by Letters Patent, is

1. In a process for forming backs for books, forming the same of asingle sheet of more or less springy or elastic material, as cardboardor the like, by folding such strip into superposed layers, uniting saidlayers along their meeting edges only by means of an adhesive substance,compressing the so-united layers in presence of heat before the adhesivehas become dry, and then shaping the same to the required form,substantially as set forth.

2. A back for books composed of a single sheet of a more or less springyor elastic material, as cardboard or the like, folded into superposedlayers united along their meeting edges only, for the purpose set forth.

3. A back for books composed of a singlesheet of more or less springy orelastic material as cardboard or the like folded in superposed layers,permanently united along their meeting edges only, and a sheet or stripof flexible material of greater width than said superposed layersconnected to the inner layer of such, substantially as and for thepurpose set forth.

In testimony that I claim the foregoing as my invention I have signed myname in presence of two subscribing witnesses.

GEORG BER-NADOTTE SOELBERG.

. WVitnesses:

OHERLoY FISCHER, A. HERMANSEN.

